A device of this class is already known. This known device has proved eminently suitable for the drive of sliding roofs of automobiles, because it requires only a limited complication of construction means to achieve a reliable limitation of revolutions, and can be housed without additional space demand in the rosette which usually surrounds the shaft head. In this known device, the limitation of the number of revolutions serves for limiting the distance of slide of the roof.
In a more modern sliding roof design the sliding roof can either be moved out in the manner of a front hinged ventilator flap by raising its rear edge, or can be slid beneath the rear roof surface, as desired. In this form of sliding roof design, the aim is so to construct the drive that it is capable of producing both the lifting out function and also the sliding function. Thus, only one operating element, for example the hand crank in the case of a hand drive, is provided for both drive functions.
In this known form of construction of a sliding roof, the device for revolutions limitation must be so constructed that it provides a limitation of revolutions both for the sliding movement and also for the lifting out movement. In general terms, the limitation device must be capable of limiting the number of revolutions of a shaft for two different movement sequences, which are however effected by the same shaft.
In a known device of the category initially described, this requirement is met in that the abutment means of the rosette block are disposed upon a slider which is mounted in the rosette block so as to be transversely adjustable to the shaft and in that they can be switched as desired into the movement path of the abutment means mounted on the ring. This known and constructionally very simple device has demonstrated its excellent functional capability in practice. In order to make the limitation of revolutions effective for the two different movement sequences, two switching positions for the slider are however necessary in this known device, which however makes the device more difficult to operate. With the known device, the operating person must note the relevant direction of rotation and the corresponding switching position, in order to produce the desired movement sequence.
The objective underlying the present invention is to simplify the operating of the device constructed for two different movement sequences to be effected by the same shaft, and especially to eliminate the need for two switching positions for the two different movement sequences.